High-pressure feedwater preheater

ABSTRACT

In a high-pressure feedwater preheater having a steam jacket and containing a collector having a free end extending through the steam jacket and provided with removable closure means at that free end, the collector includes a container part located wholly within the steam jacket, an appendage thereof forming the free end of the collector, and a welding seam located within the steam jacket and securing the appendage to the container part.

United States Patent Kelp [451 Sept. 26, 1972 [S4] HIGH-PRESSURE FEEDWATER PREHEATER [72] lnventor: Fritz Kelp, l Stettiner Str.,Erlangen, Germany [22] Filed: July 19, 1971 [21] Appl. No.: 163,653

[ 1 Foreign Application Priority Data Julyl8,l970 Germany ..G7027|87.3

[52] U.S. Cl ..122/32, 165/158 [51] Int. Cl. ..F22b 1/16 [58] Field ofSearch ..122/32; 165/158, 163

[56] References Cited UNITED STATES PATENTS 3,228,463 l/l966 Kagi..165/163 X 3,356,135 12/1967 Sayre ..l22/32X Primary Examiner-KennethW. Sprague AttorneyCurt M. Avery et a1.

[57] ABSTRACT In a high-pressure feedwater preheater having a steamjacket and containing a collector having a free end extending throughthe steam jacket and provided with removable closure means at that freeend, the collector includes a container part located wholly within thesteam jacket, an appendage thereof forming the free end of thecollector, and a welding seam located within the steam jacket andsecuring the appendage to the container part.

2 Claims, 1 Drawing Figure HIGH-PRESSURE FEEDWATER PREHEATER Theinvention relates to high-pressure feedwater preheater of the collectorconstruction type having a cylindrical steam jacket wherein there aredisposed an inlet collector as distributor of a heating tube systemtraversed by feedwater, and an outlet collector extendingperpendicularly to the longitudinal axis of the steam jacket. The freeend of at least one of the two collectors is welded to the steam jacketand has an inspection opening and a branch for feedwater supply and adischarge passing through the steam jacket in the immediate vicinity ofthe end of the collector formed with the inspection opening. Both of thefeedwater lines are located at the same level opposite one another atthe cylindrical steam jacket.

This type of construction has the advantage of great thermal elasticityand rapid accessibility for the purpose of effecting revisions andrepairs. It requires, however, a relatively large cost of manufacture inthe conventional form thereof, because a large number of heating tubeconnections must be welded to the collectors which are secured in thesteam jackets. The accessibility is consequently very restricted forthis work so that the welds are very difficult to produce and the numberof possible connections are unnecessarily limited.

One might consider producing the steam jacket in the vicinity thereof atwhich the connections aire made to the collectors, of two half shellsand, after welding them together, toweld the heating tubes to thecollectors and the collecting lines for the feedwater. This method ofavoiding the aforementioned disadvantages, causes other disadvantages,however, because the half shells are rather difficult to manufactureand, due to the necessary wall thicknesses, deformations and residualstresses occur at the welds which are not permissible or safe.

It is accordingly an object of the invention to provide high-pressurefeedwater preheater wherein the collectors and the connecting lines areformed respectively of two or more parts so that the welding operationsof the heating tubes can be performed outside the steam jacket beforethe latter is placed over the tube system.

More specifically, in accordance with a further feature of theinvention, it is an object of the invention to provide such feedwaterpreheater wherein, after introducing the heating tubes and thecollectors therefor into the steam jacket, the outer parts of thecollectors and the connecting lines can be welded to the similar partslocated therewithin and to the steam jacket.

in accordance with another object of the invention the tube weldingseams can be effected inside the tubes so that good accessibility andpossibility of testing are facilitated.

A further object of the invention is to provide connections at aconventionally manufactured steam jacket that is produced withoutdifficulty and substantially free of stress, since the possibility isprovided of connecting separate connecting members between theconnecting lines and the steam jacket.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, high-pressure feedwater preheatercomprising a cylindrical steam jacket, a heating tube system locatedwithin the steam jacket and traversible by feedwater, an inlet collectorconnected to the heating tube system and serving as distributor of thefeedwater thereto, an outlet collector also connected to the heatingtube system and disposed perpendicularly to the longitudinal axis of thesteam jacket, at least one of the collectors having a free end extendingthrough the steam jacket, a closeable inspection opening formed in thefree end, a connecting tube for the feedwater connected to each of thecollectors, at least one of the connecting tubes being secured in thesteam jacket in immediate vicinity of the free collector end formed withthe inspection opening, both of the connecting tubes extending outsidethe steam jacket at substantially the same level opposite one another,the collectors including, respectively, a container part located whollywithin the steam jacket, an appendage thereto forming the free end and awelding seam located within the steam jacket and securing the appendageto the container part and the connecting tubes including, respectively,a connecting elbow wholly within the steam jacket, a connecting tubeportion partly extending from the steam jacket, and a welding seamlocated within the steam jacket and securing the connecting elbow to theconnecting tube portion.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin high-pressure feedwater preheater, it is nevertheless not intended tobe limited to the details shown, since various modifications andstructural changes may be made therein without departing from the spiritof the invention and within the scope and range of equivalents of theclaims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying single FIGURE of the drawing.

The FIGURE of the drawing shows a diagrammatic longitudinalcross-sectional view of a high-pressure feedwater preheater constructedin accordance with the invention.

As shown in the figure, feedwater flows in direction of the arrow at theright-hand side of the figure, through a connecting line l and an elbow9 into a collector 6 acting as a distributor and flows therefrom througha multiplicity of heating tubes 11 into a condensate cooling zone 13,then up through non-illustrated lengths of heating tubes 11 anddownwardly through the heating tube lengths 10 into a condensation andpossibly heat-removing zone located generally at the top of the figure,from which the feedwater flows into another collector 6 after which,having traversed a second elbow 9 extending from the last-mentionedcollector 6, the feedwater discharges from the high-pressure preheaterthrough the connecting line 2 in the direction of the arrow shown at theleft-hand side of the figure.

Superheated steam enters the steam jacket 5 of the high-pressurefeedwater preheater of the invention through an inlet line 3 in thedirection of the arrow shown at the top of the figure. The super heatedsteam condenses at the heating tube lengths 10. The condensate of thesuperheated steam is subcooled at the tube lengths l1 and dischargesthrough the outlet line 4 in the direction of the arrow shown at thebottom of the figure.

The manufacture or assembly of the high-pressure feedwater preheater ofthe invention is carried out as follows:

The heating tubes and 11 are welded to the collectors 6, respectively,with are provided with respective tube elbows 9. After this tube systemis completely welded together, the steam jacket 5 is slid over the same.Appendages 8 of the collectors 6 are then welded at the seam 14 to thecontainer part of the collectors 6 already located in the steam jacket 5and are also welded to the steam jacket 5 at the opening of the latterthrough which the appendages 8 extend out of the latter. While theappendages, 8 are being welded to the basic container part of thecollectors 8, the closure member or stopper 7 is removed from theappendage 8. After the welding of these parts together has beencompleted, the stopper 7 'isthen suitably inserted and retained thereinby conventional means. The feedwater inlet line 1 and the outlet line 2are inserted through suitable openings formed in the steam jacket andare welded at to the respective elbows 9. Bell-like connecting members12 are then welded respectively to the individual lines 1 and 2 and theoutlet surface of the steam jacket in order to permit compensation formanufacturing tolerances. Also, by means of using the connecting members12, a thermally elastic connection is produced between the steam jacketand the feedwater lines 1 and 2, which is also able to absorb well andsafely line forces from the connecting lines.

The preheater of the invention of the instant application combinesthermally elastic construction with advantageous use of the steam jacketinterior volumne since it is possible to provide all of the heatingtubes that are to be located therein with relatively good access to thewelds due to the production of the welding connections at the collectors6 outside of the steam jacket 5. The welding seams that are to be madeafter assembly of the steam jacket 5 with the heating tube system, arecircular welds which may be produced simply with no vproblems becausecircular welds or cylindrical members require the absorption of onlyabout half of the operating stresses as to longitudinal or elongatedwelds.

I claim:

1. High-pressure feedwater preheater comprising a cylindrical steamjacket, a heating tube system located within said steam jacket andtraversible by feedwater, an inlet collector connected to said heatingtube system and serving as distributor of the feedwater thereto, anoutlet collector also connected to said heating tube system, anddisposed perpendicularly to the longitudinal axis of said steam jacket,at least one of said collectors having a free end extending through saidsteam jacket, a closeable inspection opening formed in said free end, aconnecting tube for the feedwater connected to each of said collectorsat least one of said connecting tu bes being secured in said steamjacket in immediate vicinity of the free collector end formed with saidinspection opening, both of said connecting tubes extending outside saidsteam jacket at substantially the same level opposite one another, saidcollectors including, respectively, a container part located whollywithin said steam jacket, an appendage thereto forming said free end anda welding seam located within said steam jacket and securing saidappendage to said container part, and said connecting tubes including,respectively, a connecting elbow wholly within said steam jacket, aconnecting tube portion partly extending from said steam jacket, and awelding seam located within said steam jacket and securing saidconnecting elbow to said connecting tube portion.

2. High-pressure feedwater preheater according to claim 1 wherein saidconnecting tubes extend with clearance through respective openingsformed in said steam jacket, and including connecting means locatedoutside said steam jacket and connecting said connecting tubesrespectively to said steam jacket.

1. High-pressure feedwater preheater comprising a cylindrical steamjacket, a heating tube system located within said steam jacket andtraversible by feedwater, an inlet collector connected to said heatingtube system and serving as distributor of the feedwater thereto, anoutlet collector also connected to said heating tube system, anddisposed perpendicularly to the longitudinal axis of said steam jacket,at least one of said collectors having a free end extending through saidsteam jacket, a closeable inspection opening formed in said free end, aconnecting tube for the feedwater connected to each of said collectorsat least one of said connecting tubes being secured in said steam jacketin immediate vicinity of the free collector end formed with saidinspection opening, both of said connecting tubes extending outside saidsteam jacket at substantially the same level opposite one another, saidcollectors including, respectively, a container part located whollywithin said steam jacket, an appendage thereto forming said free end anda welding seam located within said steam jacket and securing saidappendage to said container part, and said connecting tubes including,respectively, a connecting elbow wholly within said steam jacket, aconnecting tube portion partly extending from said steam jacket, and awelding seam located within said steam jacket and securing saidconnecting elbow to said connecting tube portion.
 2. High-pressurefeedwater preheater according to claim 1 wherein said connecting tubesextend with clearance through respective openings formed in said steamjacket, and including connecting means located outside said steam jacketand connecting said connecting tubes respectively to said steam jacket.